First of all 'tonal changes' doesn't make sense in that context. And second, that is a pretty poor of an excuse to dislike the promo because of the tonality in his voice. The whole point of the segment was to show the respect Heyman has for him and believes he is powerful wrestler (which he has done so in the past with other superstars) but also to tell him it doesn't matter because Lesnar is plain better. What Reigns says, is that he doesn't care about respect anymore and he's out to take Lesnar out. Simple as that.
The segment was good, stop your whining about Reigns being in the main event and not Bryan or Ziggler. Deal with it